This is a work in progress I will include a BOM when I have completed the build.
Open Scope is an F5 Newtonian telescope designed to be printed on most printers. it is based on the Ultrascope by OSA (http://www.openspaceagency.com/ultrascope). Use this as the focuser https://www.thingiverse.com/thing:4424419.
The author hasn't provided the model origin yet.